多对多双向关联

老师和学生：

 

Annotation配置：

package com.zchen.hibernate.manytmany;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Entity
@Table(name="T_TEACHER")
public class Teacher {
	private int id;
	private String name;
	
	private Set<Student> students = new HashSet<Student>();
	
	@ManyToMany
	@JoinTable(name="T_S",
			joinColumns={@JoinColumn(name="TEACHER_ID")},
			inverseJoinColumns={@JoinColumn(name="STUDENT_ID")}
	)
	public Set<Student> getStudents() {
		return students;
	}
	public void setStudents(Set<Student> students) {
		this.students = students;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	

}

 

package com.zchen.hibernate.manytmany;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Entity
@Table(name="T_STUDENT")
public class Student {
	private int id;
	private String name;
	
	private Set<Teacher> teachers = new HashSet<Teacher>();
	
	@ManyToMany(mappedBy="students")
	public Set<Teacher> getTeachers() {
		return teachers;
	}
	public void setTeachers(Set<Teacher> teachers) {
		this.teachers = teachers;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	

}

 

Xml配置：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.zchen.hibernate.manytmany">

    <class name="Teacher" table="T_TEACHER">
        <id name="id" column="ID">
            <generator class="native">
            </generator>
        </id>
        <property name="name" column="NAME"/>
        <set name="Students" table="T_S">
        	<key column="TEACHER_ID"></key>
        	<many-to-many class="com.zchen.hibernate.manytmany.Student" column="STUDENT_ID"/>
        </set>
    </class>

</hibernate-mapping>

 

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.zchen.hibernate.manytmany">

    <class name="Student" table="T_STUDENT">
        <id name="id" column="ID">
            <generator class="native">
            </generator>
        </id>
        <property name="name" column="NAME"/>
      
	    <set name="teachers" table="T_S">
        	<key column="STUDENT_ID"></key>
        	<many-to-many class="com.zchen.hibernate.manytmany.Student" column="TEACHER_ID"/>
        </set> 
    </class>

</hibernate-mapping>

 

<?xml version="1.0"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                         "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
 <session-factory name="">
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="connection.url">jdbc:mysql:///db_czbk_hibernate</property>
  <property name="connection.username">root</property>
  <property name="connection.password">1234</property>
  <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
  <property name="hbm2ddl.auto">create</property>
  <property name="current_session_context_class">thread</property>
  <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
  <property name="show_sql">true</property>
  <!-- <mapping class="com.zchen.hibernate.manytmany.Teacher"/>
  <mapping class="com.zchen.hibernate.manytmany.Student"/>  -->
  
  <mapping resource="com/zchen/hibernate/manytmany/Teacher.hbm.xml" />
  <mapping resource="com/zchen/hibernate/manytmany/Student.hbm.xml" />
  
 </session-factory>
</hibernate-configuration>

 

package com.zchen.hibernate;

import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class Snippet {
	@Test
	public void testSchemaExport(){
			new SchemaExport(new AnnotationConfiguration().configure()).create(true, true);
	}
}